Spinneret cleaning apparatus



Sheet Filed Oct. 6, 1966 FIG.

J 7. F 2 2 I I |H.||.||| 0|.|IIII IIL\ 2 AIM I]. II a i 6 o INVENTOR RQCHAR D YOU NG HAYS ATTORNEY Sheet 2 of 2 Filed Oct. 6, 1966 FIG-2 INVENTOR RICHARD YOUNG HAYS BY MMM ATTORNEY United States Patent 3,436,789 SPINNERET CLEANING APPARATUS Richard Young Hays, Kiuston, N.C., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware Filed Oct. 6, 1966, Ser. No. 584,773 Int. Cl. A471 5/14, 5/00 US. Cl. -345 1 Claim ABSTRACT OF THE DISCLOSURE This invention relates to spinnerets and, more particularly, to an apparatus for cleaning the air passageways in a hollow filament spinneret without removing the spinneret from service.

It is known in the prior art to spin hollow filaments from organic materials by drawing room air into the core of the filament through internal passageways in the spinneret. One of the important goals in the melt spinning art has been ways to effect longer periods of spinning without interruption for removal and cleaning of spinnerets. One problem affecting spinneret life arises because the organic materials spun in the melt will occasionally leave a small carbonized deposit at the spinning orifice which tends to block the orifice and accumulate molten polymer resulting in a decrease in size of the hollow portion of the filament. Additionally, these. accumulations may be of a size to deflect the filament being extruded, to slow down the extrusion or even hold back the extrusion until a mass of polymer drips from the orifice. The accepted method to correct this condition is to wipe the spinneret face with a brass stick to cleanse the surface. While this method is satisfactory for conventional spinnerets, when hollow filament spinnerets are wiped the passageway for room air feed to the fiber hollow becomes plugged and the spinneret must be changed for cleaning. This interruption of the spinning process, for changing the spinneret, represents lost production and must, therefore, be minimized.

With this in mind, the principal object of this invention is to provide a means to clean the internal core fluid passageways of a hollow filament spinneret without removing the spinneret from service.

According to the present invention, the spinneret passageways, for supplying fluid to the interior of a hollow filament extruded from the spinneret, are cleaned without removing the spinneret from service by using a portable apparatus. The apparatus includes, a base, a pair of spaced upstanding continuous walls fastened to the base, means to supply pressurized fluid between the walls and exhaust means to remove the fluid from the apparatus. When the apparatus is positioned against a spinneret pack assembly first and second chambers are formed, the first chamber being bounded by the outer and inner walls, the spinneret and its retaining ring, with the second chamber being bounded by the spinneret face the inner wall and the base. The pressurized fluid applied flows through the fluid supply passages in the spinneret removing pluggage that has occurred and is exhausted from the apparatus.

The invention will be further illustrated by reference to the following drawings in which:

Patented Apr. 8, 1969 FIGURE 1 is a fragmentary section view of an installed spinneret with the cleaning enclosure operably associated with the spinneret.

FIGURE 2 is a top view of the cleaning enclosure.

FIGURE 3 is a side view of FIGURE 2.

In FIGURE 1 the base of a spinning machine is represented by the number 40. A spinneret assembly generally designated as 48 is fastened to the base 40 by means of retaining ring 44 shouldered against spinneret 42 and bolts 46. Molten polymer to be spun is brought to the spinneret 42 through ports 41 in distribution plate 50 by means of a pump or other suitable metering means. The molten polymer composition moves into bore 60 of insert 52 fitted in the spinneret capillary, then it is distributed through holes 62 and passes through an outlet in the spinneret face 49 to form a hollow filament. The outlet is defined by the cylindrical portion 64 of insert 52 and portion '66 of the spinneret capillary. As the polymer coalesces around portion 64 at the end of insert 52, a partial vacuum is formed drawing room air from the space between ring 44 and spinneret 42 through the combined bores 58, 54 and 56 into the center of the filament equalizing the pressure on the filament walls to prevent the filament from collapsing.

A cleaning apparatus, shown positioned against spinneret assembly 48, includes a base 18 having a handle 20 fastened to it by bolt 22. Also attached to base 18 is an upstanding continuous inner wall 14, which extends upwardly and outwardly from the base. An upstanding continuous outer Wall 12 is attached to a continuous spacer 16 which in turn is fastened to wall 14, thus forming two cavities, one within the other. When the apparatus is engaged as shown in FIGURE 1 the outer wall 12 telescopes into ring 44 forming a first chamber 17 and the inner wall 14 abuts the edge of spinneret face 49 to form a second chamber 15. An exhaust port 30 is provided through walls 12 and 14 to exhaust the second chamber 15 to atmosphere. Conduit 24 sealed to an opening in spacer 16 is connected to a source of pressurized fluid 23 through hose 26 attached to conduit 24 by clamp 28.

Referring to FIGURES 2 and 3, an expansion slot 32 is cut partially through the width of the outermost wall 12. A cover plate 34 for the slot 32 is fastened along one vertical edge 33 to the inside of wall 12. The slot is necessary to allow for slight variations in the size of spinneret assembly parts and to maintain a leak-free fit at the spinneret.

During periodic wiping of the spinneret face, it is very probable that bore 56 Will become plugged with polymer which previously required removal of the spinneret assembly 48 from the spinning machine for cleaning or unplugging. In accordance with the invention, when a pluggage occurs, it is only necessary to place the apparatus 10 in the position shown in FIGURE 1. Then by admitting presurized cleaning fluid through pipe 24, the fluid will flow into the chamber 17 then through bores 58, 5'4, and 56 with enough force to clean any pluggage from bore 56, thus eliminating the need to change the spinneret 42. The material blown from the spinneret is retained in chamber 15 while the pressurized fluid is exhausted from chamber 15 to atmosphere through port 30.

While this invention has been described for use with a round spinneret assembly, it would be obvious to adapt the cleaning enclosure for use with other spinneret shapes, such as rectangular, square, or oval. Steam is preferred as the cleaning fluid, however inert gas or compressed air would be suitable for use.

Many modifications and adaptations will be apparent to those skilled in the art without departing from the spirit of the invention which is accordingly intended to be limited only by the scope of the appended claims.

What is claimed is:

1. An apparatus for in service cleaning of a hollow filament spinneret pack assembly having a ring for retaining a spinneret provided with filament core fluid supply passages wherein the supply passages terminate substantially at the spinneret face and are vented in a space between the spinneret and the spinneret retaining ring, said apparatus comprising: a base; a pair of spaced upstanding continuous walls fastened to the base, said walls and base forming two cavities, one within the other, the outermost of said walls being flexible and extending beyond the inner wall and having means therein for allowing flexing movement of the outermost wall to permit sealed telescoping engagement with said retaining ring, the inner Wall being adapted to engage said spinneret so that said one cavity encloses the spinneret face and said other cavity encloses the space bet-ween the spinneret and the retaining ring; exhaust means in communication 4 with said one cavity; and means connected to said other cavity to supply pressurized fluid thereto so that when the apparatus is engaged with the spinneret assembly pressurized fluid will flow through the core fluid supply passages to said one cavity and be exhausted therefrom.

References Cited UNITED STATES PATENTS 787,732 4/ 1905 Dort 15345 858,911 7/1907 Richter. 3,186,132 6/1965 Duncan et al.

ROBERT W. MIT CH-ELL, Primary Examiner.

US. Cl. X.'R. 

